This invention relates to lawn sprinkler systems, and more particularly to an improved sprinkler head assembly for such systems.
In lawn sprinkler systems, water supply pipes are buried in the lawn slightly below ground level and water taps or outlets are provided at a plurality of locations, each tap having a sprinkler head located near ground level for directing the supply of water to the lawn in which the lawn sprinkler system is installed. The sprinkler heads both limit the rate of flow of water from the water supply pipes and define a spray pattern typically over an area 360.degree. around the sprinkler head. Because the sprinkler heads and risers are located above or slightly below ground level, the sprinkler heads may be knocked off inadvertently due to being struck by a lawn mower, because of vandalism, or for other reasons. If, for any reason, a sprinkler head is not in place when water under pressure is supplied to the water supply pipes of the lawn sprinkling system, water will flow freely and uncontrolled through the tap that is missing its associated sprinkler head. This will result both in waste of water, and in the flooding with water of a very small area of the lawn which could result in damage to the lawn, plants and the subsoil. The waste of water and the potential damage to a lawn could be extensive for lawn sprinkler systems controlled by a timer. In such systems, water is supplied to the water supply pipes automatically and periodically and wasting of water could continue unnoticed for extended periods of time.